Apple's home computer of 1977, one of the first mass-produced personal computers with color graphics. Many artists and game makers started on it.
The Apple II (1977), Commodore 64 (1982) and Commodore Amiga (1985) all represent enough of a change, moving out of the research labs and into artist studios, that it's a whole other era.
Casey Reas, Casey Reas on the History of Generative Art - Part 2
I actually had obtained an Apple II computer on a grant when I was at the university.
Joan Truckenbrod, The 1970s Artist-Programmer: Truckenbrod, Dehlinger